The present invention generally relates to a transmitter and, more particularly, to a carrier generator for generating a carrier at a frequency of interest.
In a wireless communication system, information or data to be transmitted from a transmitter may be conveyed by a carrier generated by the transmitter. FIG. 1 is a schematic block diagram of a conventional wireless transmitter 10. Referring to FIG. 1, the wireless transmitter 10 may include a quartz crystal 11, a crystal circuit 12, a phase-frequency detector (PFD) 13, a charge pump (CP) 14, a low pass filter (LPF) 15, a voltage-controlled oscillator (VCO) 16, a divider 17, a power amplifier (PA) 18 and an antenna 19. The above-mentioned components 13 to 17 may form a phase-locked loop (PLL) circuit of the wireless transmitter 10. The PA 18, which may comprise active components, is used to drive an antenna and translate a signal level and may thus require a considerable amount of power during operation. A transmitter with the PA 18 may not satisfy the increasing demand for communication devices with low power consumption and low cost.